Filter



FIG. 1 is a perspective view of a filter showing my new design;

FIG. 2 is a side elevational view thereof;

FIG. 3 is an opposite side elevational thereof;

FIG. 4 is a front elevational view thereof;

FIG. 5 is a rear elevational view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof. 

The ornamental design for a filter, as shown and described. 